This invention relates to flame retardant compositions containing at least one tetrahalophthalate ester and a polystyrene resin. Additionally this composition may also contain one or more brominated and/or chlorinated compounds in an amount to provide additional flame retardancy to the polystyrene resins.
Styrenic resins fine extensive use in the manufacture of packaging material, refrigerator doors, air conditioner cases; machine housings, electrical equipment, toys, clock, TV, and radio cabinets, thermal insulation, ice buckets, containers, furniture construction, appliances, dinnerware, etc. The preparation and description of polystyrene and expandable polystyrene are well known in the art. They are discussed in G. Hawley, "Condensed Chemical Encyclopedia", 10th Edition, pp 838 and 976 (1981); Kirk-Othmer "Encyclopedia of Chemical Technology", 2nd Edition, Vol. 9, pp 847-884 (1966) and Vol. 19, pp 85-134 (1969); A. E. Platt in "Encyclopedia of Polymer Science and Technology", Vol. 13, pp 156-189 (1970) and U.S. Pat. Nos. 4,281,067; 4,298,702; 4,419,458; 4,497,911; 4,548,956; 4,596,682; and 4,618,468, the teachings of which are incorporated herein by reference.
For many applications where styrenic polymers are used, there is a need to add flame retardants since these materials are flammable. Some of the applications which require flame retarded styrenics are radio and TV cabinets, toys, electrical equipment, furniture construction, etc. (See, for example, U.S. Pat. Nos. 4,341,890 and 4,548,956, the teachings of which are incorporated herein by reference.)
The use of brominated and/or chlorinated compounds by themselves or in combination with other materials such as organic phosphates, antimony compounds etc. as flame retardants for polystyrene resin compositions are well known in the art and are exemplified by U.S. Pat. Nos. 4,218,511; 4,240,953; 4,244,825; 4,280,952; 4,281,067; 4,282,142; 4,341,890; 4,353,820; 4,377,407; 4,404,361; 4,419,458; 4,446,202; 4,497,911; 4,548,956; 4,596,682; and 4,618,468. The teachings of the aforesaid patents are incorporated herein by reference.
Tetrahalophthalate esters have been used as flame-proofing materials. For example, U.S. Pat. No. 4,098,704 describes the use of these materials as textile finishing agents. U.S. Pat. Nos. 4,298,517 and 4,397,977 disclose these compounds as flame retardants for halogenated resins. However, no teachings have been found which slow these compounds as flame retardants or processing aids for polystyrene resins.